A British sniper currently holds the publicly known record for a confirmed kill shot. As a Corporal of Horse in the British Army, Craig Harrison used a .338 caliber L115A3 Long Range Rifle to shoot a man from 2,707 yards (1.54 miles) in Afghanistan in 2009.
Variability is a measure of the spread of a data set. Learn more about the different measures of variability including the range, variance, and standard deviation, and how they are used in the field of Psychology.
Standard deviation is the most common measure of variability and is frequently used to determine the volatility of stock markets or other investments. To calculate the standard deviation, you must first determine the variance.he standard deviation is simply the square root of the variance. Squaring the differences between each point and the mean avoids the issue of negative differences for values below the mean, but it means the variance is no longer in the same unit of measure as the original data.